340 research outputs found

    The HITRAN2016 Molecular Spectroscopic Database

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    This paper describes the contents of the 2016 edition of the HITRAN molecular spectroscopic compilation. The new edition replaces the previous HITRAN edition of 2012 and its updates during the intervening years. The HITRAN molecular absorption compilation is composed of five major components: the traditional line-by-line spectroscopic parameters required for high-resolution radiative-transfer codes, infrared absorption cross-sections for molecules not yet amenable to representation in a line-by-line form, collision-induced absorption data, aerosol indices of refraction, and general tables such as partition sums that apply globally to the data. The new HITRAN is greatly extended in terms of accuracy, spectral coverage, additional absorption phenomena, added line-shape formalisms, and validity. Moreover, molecules, isotopologues, and perturbing gases have been added that address the issues of atmospheres beyond the Earth. Of considerable note, experimental IR cross-sections for almost 300 additional molecules important in different areas of atmospheric science have been added to the database. The compilation can be accessed through www.hitran.org. Most of the HITRAN data have now been cast into an underlying relational database structure that offers many advantages over the long-standing sequential text-based structure. The new structure empowers the user in many ways. It enables the incorporation of an extended set of fundamental parameters per transition, sophisticated line-shape formalisms, easy user-defined output formats, and very convenient searching, filtering, and plotting of data. A powerful application programming interface making use of structured query language (SQL) features for higher-level applications of HITRAN is also provided

    Does shade improve light interception efficiency? A comparison among seedlings from shade-tolerant and -intolerant temperate deciduous tree species

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    • Here, we tested two hypotheses: shading increases light interception efficiency (LIE) of broadleaved tree seedlings, and shade-tolerant species exhibit larger LIEs than do shade-intolerant ones. The impact of seedling size was taken into account to detect potential size-independent effects on LIE. LIE was defined as the ratio of mean light intercepted by leaves to light intercepted by a horizontal surface of equal area. • Seedlings from five species differing in shade tolerance (Acer saccharum, Betula alleghaniensis, A. pseudoplatanus, B. pendula, Fagus sylvatica) were grown under neutral shading nets providing 36, 16 and 4% of external irradiance. Seedlings (1- and 2-year-old) were three-dimensionally digitized, allowing calculation of LIE. • Shading induced dramatic reduction in total leaf area, which was lowest in shade-tolerant species in all irradiance regimes. Irradiance reduced LIE through increasing leaf overlap with increasing leaf area. There was very little evidence of significant size-independent plasticity of LIE. • No relationship was found between the known shade tolerance of species and LIE at equivalent size and irradiance

    Submarine record of volcanic island construction and collapse in the Lesser Antilles arc: First scientific drilling of submarine volcanic island landslides by IODP Expedition 340

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    IODP Expedition 340 successfully drilled a series of sites offshore Montserrat, Martinique and Dominica in the Lesser Antilles from March to April 2012. These are among the few drill sites gathered around volcanic islands, and the first scientific drilling of large and likely tsunamigenic volcanic island-arc landslide deposits. These cores provide evidence and tests of previous hypotheses for the composition and origin of those deposits. Sites U1394, U1399, and U1400 that penetrated landslide deposits recovered exclusively seafloor-sediment, comprising mainly turbidites and hemipelagic deposits, and lacked debris avalanche deposits. This supports the concepts that i/ volcanic debris avalanches tend to stop at the slope break, and ii/ widespread and voluminous failures of pre-existing low-gradient seafloor sediment can be triggered by initial emplacement of material from the volcano. Offshore Martinique (U1399 and 1400), the landslide deposits comprised blocks of parallel strata that were tilted or micro-faulted, sometimes separated by intervals of homogenized sediment (intense shearing), while Site U1394 offshore Montserrat penetrated a flat-lying block of intact strata. The most likely mechanism for generating these large-scale seafloor-sediment failures appears to be propagation of a decollement from proximal areas loaded and incised by a volcanic debris avalanche. These results have implications for the magnitude of tsunami generation. Under some conditions, volcanic island landslide deposits comprised of mainly seafloor sediment will tend to form smaller magnitude tsunamis than equivalent volumes of subaerial block-rich mass flows rapidly entering water. Expedition 340 also successfully drilled sites to access the undisturbed record of eruption fallout layers intercalated with marine sediment which provide an outstanding high-resolution dataset to analyze eruption and landslides cycles, improve understanding of magmatic evolution as well as offshore sedimentation processes. This article is protected by copyright. All rights reserved

    Rapid onset of mafic magmatism facilitated by volcanic edifice collapse

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    Volcanic edifice collapses generate some of Earth's largest landslides. How such unloading affects the magma storage systems is important for both hazard assessment and for determining long-term controls on volcano growth and decay. Here we present a detailed stratigraphic and petrological analyses of volcanic landslide and eruption deposits offshore Montserrat, in a subduction zone setting, sampled during Integrated Ocean Drilling Program Expedition 340. A large (6–10 km3) collapse of the Soufrière Hills Volcano at ~130 ka was followed by explosive basaltic volcanism and the formation of a new basaltic volcanic center, the South Soufrière Hills, estimated to have initiated <100 years after collapse. This basaltic volcanism was a sharp departure from the andesitic volcanism that characterized Soufrière Hills' activity before the collapse. Mineral-melt thermobarometry demonstrates that the basaltic magma's transit through the crust was rapid and from midcrustal depths. We suggest that this rapid ascent was promoted by unloading following collapse

    The HITRAN2016 molecular spectroscopic database

    Get PDF
    This paper describes the contents of the 2016 edition of the HITRAN molecular spectroscopic compilation. The new edition replaces the previous HITRAN edition of 2012 and its updates during the intervening years. The HITRAN molecular absorption compilation is composed of five major components: the traditional line-by-line spectroscopic parameters required for high-resolution radiative-transfer codes, infrared absorption cross-sections for molecules not yet amenable to representation in a line-by-line form, collision-induced absorption data, aerosol indices of refraction, and general tables such as partition sums that apply globally to the data. The new HITRAN is greatly extended in terms of accuracy, spectral coverage, additional absorption phenomena, added line-shape formalisms, and validity. Moreover, molecules, isotopologues, and perturbing gases have been added that address the issues of atmospheres beyond the Earth. Of considerable note, experimental IR cross-sections for almost 300 additional molecules important in different areas of atmospheric science have been added to the database. The compilation can be accessed through www.hitran.org. Most of the HITRAN data have now been cast into an underlying relational database structure that offers many advantages over the long-standing sequential text-based structure. The new structure empowers the user in many, ways. It enables the incorporation of an extended set of fundamental parameters per transition, sophisticated line-shape formalisms, easy user-defined output formats, and very convenient searching, filtering, and plotting of data. A powerful application programming interface making use of structured query language (SQL) features for higher-level applications of HITRAN is also provided. Published by Elsevier Ltd

    The measurement of social stratification : comparative perspectives between Europe and Latin America

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    Production of INCASI Project H2020-MSCA-RISE-2015 GA 691004This chapter analyses compared social stratification in three Latin American countries (Argentina, Chile and Uruguay) and four European countries (Finland, France, Spain, Great Britain). We focus on both external and internal borders of social classes, as well as on the challenges posed by their analysis for sociology. We compare social classes using EGP6 in relation to a variety of social indicators, to examine how social classes vary among countries. We include debates on production models and welfare state policies to understand the specific configurations and compare the conditions of some of the INCASI countries regarding social stratification. Lastly, we apply a latent class analysis to validate the number of social classes and to recognise class boundaries

    Rapid onset of mafic magmatism facilitated by volcanic edifice collapse: MAFIC MAGMATISM FACILITATED BY VOLCANIC EDIFICE COLLAPSE

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    Volcanic edifice collapses generate some of Earth's largest landslides. How such unloading affects the magma storage systems is important for both hazard assessment and for determining long-term controls on volcano growth and decay. Here we present a detailed stratigraphic and petrological analyses of volcanic landslide and eruption deposits offshore Montserrat, in a subduction zone setting, sampled during Integrated Ocean Drilling Program Expedition 340. A large (6–10 km3) collapse of the Soufrière Hills Volcano at ~130 ka was followed by explosive basaltic volcanism and the formation of a new basaltic volcanic center, the South Soufrière Hills, estimated to have initiated <100 years after collapse. This basaltic volcanism was a sharp departure from the andesitic volcanism that characterized Soufrière Hills' activity before the collapse. Mineral-melt thermobarometry demonstrates that the basaltic magma's transit through the crust was rapid and from midcrustal depths. We suggest that this rapid ascent was promoted by unloading following collapse

    The 2009 edition of the GEISA spectroscopic database

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    The updated 2009 edition of the spectroscopic database GEISA (Gestionet Etudedes Informations Spectroscopiques Atmospheriques ; Management and Study of Atmospheric Spectroscopic Information) is described in this paper. GEISA is a computer-accessible system comprising three independent sub-databases devoted, respectively, to: line parameters, infrared and ultraviolet/visible absorption cross-sections, microphysical and optical properties of atmospheric aerosols. In this edition, 50 molecules are involved in the line parameters sub-database, including 111 isotopologues, for a total of 3,807,997 entries, in the spectral range from 10-6 to 35,877.031cm-1. GEISA, continuously developed and maintained at LMD (Laboratoirede Meteorologie Dynamique, France) since 1976, is implemented on the IPSL/CNRS(France) ‘‘Ether’’ Products and Services Centre WEB site (http://ether.ipsl.jussieu.fr), where all archived spectroscopic data can be handled through general and user friendly associated managements of software facilities. More than 350 researchers are registered for online use of GEISA

    Hydrothermal alteration of andesitic lava domes can lead to explosive volcanic behaviour

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    Dome-forming volcanoes are among the most hazardous volcanoes on Earth. Magmatic outgassing can be hindered if the permeability of a lava dome is reduced, promoting pore pressure augmentation and explosive behaviour. Laboratory data show that acid-sulphate alteration, common to volcanoes worldwide, can reduce the permeability on the sample lengthscale by up to four orders of magnitude and is the result of pore- and microfracture-filling mineral precipitation. Calculations using these data demonstrate that intense alteration can reduce the equivalent permeability of a dome by two orders of magnitude, which we show using numerical modelling to be sufficient to increase pore pressure. The fragmentation criterion shows that the predicted pore pressure increase is capable of fragmenting the majority of dome-forming materials, thus promoting explosive volcanism. It is crucial that hydrothermal alteration, which develops over months to years, is monitored at dome-forming volcanoes and is incorporated into real-time hazard assessments
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